Technical Field
The disclosure relates to a printing apparatus, and particularly relates to a three-dimensional printing apparatus.
Description of Related Art
With advancement in computer-aided manufacturing (CAM), a three dimensional printing technology has been developed in the manufacturing industry. With the technology, products can be rapidly manufactured from an original design concept. The three-dimensional printing, in fact, is a general term of a series of rapid prototyping (RP) techniques, and the concept thereof is laminate manufacturing. Specifically, a rapid prototyping machine is used to form cross-sectional shapes of a workpiece in the X-Y plane through scanning, shift intermittently at a layer thickness in the Z coordinates, and ultimately form three-dimensional objects. The three-dimensional printing technology is unrestrictedly applicable for geometric shapes, and the RP technology produces excellent outputs particularly for complex parts, which saves efforts and processing time significantly. Therefore, the digital three-dimensional printing technology is capable of presenting an object of a digital three-dimensional model designed by means of computer-aided design (CAD) software under the requirement of limited time for the user to touch and actually feel the geometry of the model. Furthermore, the assembling properties of parts, or even functional tests, can be conducted.
Currently, several ways to form thin cross-sectional layers have been developed. Taking the technique of forming a three-dimensional structure by using a powder-like modeling material, for example, such technique is implemented by spreading a powder layer (e.g., a powder-like ceramic material, a powder-like metal material, or a powder-like plastic material) with a thickness about 100 micrometers on a supporting surface, and using a specifically designed printing mechanism to eject a glue material to the powder, so as to adhere the powder in a specific region to form a layer. The process is repetitively performed to sequentially form powder layers. The powder layers are stacked with respect to each other to form a three-dimensional object.
To evenly spread the powder on the supporting surface, a powder supplying mechanism moves from an initial preparation position at one end of a printing machine to another end of the printing machine, so as to evenly spread the powder on the supporting surface. In a conventional design integrating the printing mechanism and the powder spreading mechanism, the powder spreading mechanism needs to wait until the printing mechanism completes printing to move back to the initial preparation position. Alternatively, in another conventional design where a moving path of the printing mechanism and a moving path of the powder spreading mechanism are perpendicular to each other, the printing mechanism needs to wait until the powder supplying machine moves back to the initial preparation position to start moving and spreading the glue material to the powder. Thus, a three-dimensional printing efficiency of such technique is still low, and thus fails to meet the requirements of a rapid and high yield rate.